feat: enforce resolved catalog path roles

Launcher.Next.Infrastructure/FileSystemCatalogPackageAcquirer.cs

@@ -7,14 +7,14 @@ namespace Launcher.Next.Infrastructure;
 /// local immutable staging by <see cref="IPackageSynchronizer"/>; it is never
 /// an active launch root.
 /// </summary>
-public sealed class FileSystemCatalogPackageAcquirer(string catalogRoot) : IPackageCatalogPackageAcquirer
+public sealed class FileSystemCatalogPackageAcquirer(ResolvedCatalogRoot catalogRoot) : IPackageCatalogPackageAcquirer
 {
     private const int MaxFiles = 256;
     private const long MaxBytes = 512L * 1024 * 1024;
 
     public async Task<CatalogPackage?> AcquireAsync(PackageRequirement requirement, CancellationToken cancellationToken)
     {
-        var root = Path.GetFullPath(catalogRoot);
+        var root = catalogRoot.Value;
         var candidate = Path.GetFullPath(Path.Combine(root, requirement.PackageId, requirement.RequiredVersion));
         if (!Directory.Exists(root) || IsReparsePoint(root) || !IsWithin(root, candidate) || !Directory.Exists(candidate) || IsReparsePoint(candidate))
             return null;